LSA Technology report volume 1 by Leicester School of Architecture. LSA Technology report volume 1   Published on Nov 2. Basic Elements of Passive Solar Design. Inspect. APedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website. This article discusses the Five Key Elements of Passive Solar Design and links to additional passive solar design as well as solar design evaluation questions and answers. Green links show where you are. Copyright 2. 01. 7 Inspect. Apedia. com, All Rights Reserved. Passive Solar Design Basic Considerations. Our page top photo shows windows admitting morning solar gain in a nearly balanced energy passive solar home in San Miguel de Allende, Guanajuato, Mexico. The windows in this east facing room receive morning sunlight when the home and air are cool, and is shaded in the afternoon. This is a direct gain of passive solar energy. The concrete and adobe walls form a significant thermal mass. Although the building has no central heating, temperatures remain comfortable year round, with only modest use of a small electric heater during the chilly months of December and January. Passive solar illustration. The U. S. DOE illustration left identifies the five elements of passive solar design Passive solar aperture admitting sunlightsolar energyPassive solar energy control seasonal needsPassive solar heatenergy distribution through the building. Passive solar absorber to surface absorption of energy for later release. Passive solar thermal mass providing heat storage. Five Elements of Passive Solar Home Design. The following five elements constitute a complete passive solar home design. Calculate Solar Heat Gain Through Windows And Walls' title='Calculate Solar Heat Gain Through Windows And Walls' />Each performs a separate function, but all five must work together for the design to be successful. U. S. Department of Energy. Aperture CollectorThe large glass window area through which sunlight enters the building. Typically, the apertures should face within 3. For a low cost passive solar home using lots of glass see PASSIVE SOLAR HOME, LOW COST. Absorber. The hard, darkened surface of the storage element. Calculate Solar Heat Gain Through Windows And Walls' title='Calculate Solar Heat Gain Through Windows And Walls' />We see the questions all the time people wondering What will it take to run an RV air conditioner off of solar power We get asked for advice in email regularly. Thankyou for the post As you might have seen from my comments on your oil filled heater project, I heat my house with electric power. There is one area that just. Before buying a portable air conditioner it is important to do a heat load calculation to ensure it is big enough for the intended application. Heat gain is. This surfacewhich could be that of a masonry wall, floor, or partition phase change material, or that of a water containersits in the direct path of sunlight. Sunlight hits the surface and is absorbed as heat. For an example see our articles at THERMAL MASS in BUILDINGS and see PASSIVE SOLAR FLOOR TILES, PHASE CHANGE. Thermal mass. The materials that retain or store the heat produced by sunlight. The difference between the absorber and thermal mass, although they often form the same wall or floor, is that the absorber is an exposed surface whereas thermal mass is the material below or behind that surface. For an example, see BLOCKBED RADIANT FLOORS SOLAR DESIGN. Also see SLAB INSULATION, PASSIVE SOLAR. Also see Trombe Wall. Distribution. The method by which solar heat circulates from the collection and storage points to different areas of the house. A strictly passive design will use the. In some applications, however, fans, ducts, and blowers may help with the distribution of heat through the house. See BLOCKBED RADIANT FLOORS SOLAR DESIGN. Control. Roof overhangs can be used to shade the aperture area during summer months. Other elements that control under andor overheating include electronic sensing devices, such as a differential thermostat that signals a fan to turn on operable vents and dampers that allow or restrict heat flow low emissivity blinds and. For examples see SOLAR SHADES SUNSCREENS and SUNGAIN, FILMS, LOW E GLASS. How a Passive Solar Home Design Works. To understand how a passive solar home design works, you need to understand how heat moves and how it can be stored. Photo at left, U. S. DOE, Donald AitkenAs a fundamental law, heat moves from warmer materials to cooler ones until there is no longer a temperature difference between the two. To distribute heat throughout the living space, a passive solar home design makes use of this law through the following heat movement and heat storage mechanisms Conduction. Conduction is the way heat moves through materials, traveling from molecule to molecule. Heat causes molecules close to the heat source to vibrate vigorously, and these vibrations spread to neighboring molecules, thus transferring heat energy. For example, a spoon placed into a hot cup of coffee conducts heat through its handle and into the hand that grasps it. Convection. Convection is the way heat circulates through liquids and gases. Lighter, warmer fluid rises, and cooler, denser fluid sinks. For instance, warm air rises because it is lighter than cold air, which sinks. This is why warmer air accumulates on the second floor of a house, while the basement stays cool. Some passive solar homes use air convection to carry solar heat from a south wall into the buildings interior. Radiation. Radiant heat moves through the air from warmer objects to cooler ones. There are two types of radiation important to passive solar design solar radiation and infrared radiation. When radiation strikes an object, it is absorbed, reflected, or transmitted, depending on certain properties of that object. Opaque objects absorb 4. This is why solar absorber surfaces tend to be dark colored. Bright white materials or objects reflect 8. Inside a home, infrared radiation occurs when warmed surfaces radiate heat towards cooler surfaces. For example, your body can radiate infrared heat to a cold surface, possibly causing you discomfort. These surfaces can include walls, windows, or ceilings in the home. Clear glass transmits 8. After solar radiation is transmitted through the glass and absorbed by the home, it is radiated again from the interior surfaces as infrared radiation. Although glass allows solar radiation to pass through, it absorbs the infrared radiation. The glass then radiates part of that heat back to the homes interior. In this way, glass traps solar heat entering the home. Thermal capacitance. Thermal capacitance refers to the ability of materials to store heat. Thermal mass refers to the materials that store heat. Thermal mass stores heat by changing its temperature, which can be done by storing heat from a warm room or by converting direct solar radiation into heat. The more thermal mass, the more heat can be stored for each degree rise in temperature. Boris Ate A Thesaurus Activities Synonyms. Masonry materials, like concrete, stones, brick, and tile, are commonly used as thermal mass in passive solar homes. Water also has been successfully used. Definition of Direct Solar Gain Direct gain is the simplest passive solar home design technique. Sunlight enters the house through the aperture collectorusually south facing windows with a glazing material made of transparent or translucent glass. The sunlight then strikes masonry floors andor walls, which absorb and store the solar heat. The surfaces of these masonry floors and walls are typically a dark color because dark colors usually absorb more heat than light colors. At night, as the room cools, the heat stored in the thermal mass convects and radiates into the room. Another example of direct solar gain is at our page top photo. DFSome builders and homeowners have used water filled containers located inside the living space to absorb and store solar heat. Water stores twice as much heat as masonry materials per cubic foot of volume. Unlike masonry, water doesnt support itself. Water thermal storage, therefore, requires carefully designed structural support. Also, water tanks require some minimal maintenance, including periodic yearly water treatment to prevent microbial growth. The amount of passive solar sometimes called the passive solar fraction depends on the area of glazing and the amount of thermal mass. The glazing area determines how much solar heat can be collected. And the amount of thermal mass determines how much of that heat can be stored. It is possible to undersize the thermal mass, which results in the house overheating. There is a diminishing return on over sizing thermal mass, but excess mass will not hurt the performance.